5y(2y³-4) = 5y *2y³ + 5y *(-4) = 10y⁴ - 20y(c-6)(c+4) =c² +4c -6c - 24 = c² - 2c - 248x² - 9x(x+2) = 8x² - 9x² -18x = -x² - 18x(2x+y)(x-7y) = 2x² - 14xy +xy -7y² =2x² - 13xy -7y²(7x + 9) - (10x -2) = 177x + 9 -10x + 2 = 17-3x + 11 = 17-3x = 17 - 11-3x = 6x = 6 : (-3)х = -2-------------------------------------(7 * (-2) + 9 ) - (10 * (-2) - 2) = 17(-14 + 9) - ( - 20 - 2) = 17- 5 - ( - 22) = 17 - 5 + 22 = 17 17 = 179 - 4(х - 3,5) = 11 - 8х9 - 4х - 4*(-3,5) = 11 - 8х9 - 4х + 14 = 11 - 8х-4х + 23 = 11 - 8х-4х + 8х = 11 - 234х = -12х = -12 : 4х = -3---------------------------------------9 - 4(-3 - 3,5) =11 - 8 *(-3)9 - 4 * (-6,5) = 11 + 249 + 26 = 3535 = 3516а² - 4а =4а*4а - 4а*1 = 4а(4а-1)5ху - х²у = ху( 5 -х)